kernel.git/drivers/pci/search.c, branch linux-5.5.y

PCI: Fix pci_add_dma_alias() bitmask size

2020-02-24T07:38:01Z

[ Upstream commit f8bf2aeb651b3460a4b36fd7ba1ba1d31777d35c ] The number of possible devfns is 256, but pci_add_dma_alias() allocated a bitmap of size 255. Fix this off-by-one error. This fixes commits 338c3149a221 ("PCI: Add support for multiple DMA aliases") and c6635792737b ("PCI: Allocate dma_alias_mask with bitmap_zalloc()"), but I doubt it was possible to see a problem because it takes 4 64-bit longs (or 8 32-bit longs) to hold 255 bits, and bitmap_zalloc() doesn't save the 255-bit size anywhere. [bhelgaas: commit log, move #define to drivers/pci/pci.h, include loop limit fix from Qian Cai: https://lore.kernel.org/r/20191218170004.5297-1-cai@lca.pw] Signed-off-by: James Sewart Signed-off-by: Bjorn Helgaas Reviewed-by: Logan Gunthorpe Signed-off-by: Sasha Levin

PCI: Unexport pci_bus_sem

2019-07-23T23:32:50Z

pci_bus_sem is not used by a loadable kernel module and does not need to be exported. It was exported by ce29ca3ea407 ("PCI: acpiphp: remove all functions in slot, even without ACPI _EJx"), which added a use of pci_bus_sem in acpiphp, which could be built as a module at that time. But since 6037a803b05e ("PCI: acpiphp: Convert acpiphp to be builtin only, not modular"), it can no longer be built as a module. Link: https://lore.kernel.org/r/20190718032951.40188-1-skunberg.kelsey@gmail.com Signed-off-by: Kelsey Skunberg Signed-off-by: Bjorn Helgaas

bus_find_device: Unify the match callback with class_find_device

2019-06-24T03:22:31Z

There is an arbitrary difference between the prototypes of bus_find_device() and class_find_device() preventing their callers from passing the same pair of data and match() arguments to both of them, which is the const qualifier used in the prototype of class_find_device(). If that qualifier is also used in the bus_find_device() prototype, it will be possible to pass the same match() callback function to both bus_find_device() and class_find_device(), which will allow some optimizations to be made in order to avoid code duplication going forward. Also with that, constify the "data" parameter as it is passed as a const to the match function. For this reason, change the prototype of bus_find_device() to match the prototype of class_find_device() and adjust its callers to use the const qualifier in accordance with the new prototype of it. Cc: Alexander Shishkin Cc: Andrew Lunn Cc: Andreas Noever Cc: Arnd Bergmann Cc: Bjorn Helgaas Cc: Corey Minyard Cc: Christian Borntraeger Cc: David Kershner Cc: "David S. Miller" Cc: David Airlie Cc: Felipe Balbi Cc: Frank Rowand Cc: Grygorii Strashko Cc: Harald Freudenberger Cc: Hartmut Knaack Cc: Heiko Stuebner Cc: Jason Gunthorpe Cc: Jonathan Cameron Cc: "James E.J. Bottomley" Cc: Len Brown Cc: Mark Brown Cc: Michael Ellerman Cc: Michael Jamet Cc: "Martin K. Petersen" Cc: Peter Oberparleiter Cc: Sebastian Ott Cc: Srinivas Kandagatla Cc: Yehezkel Bernat Cc: rafael@kernel.org Acked-by: Corey Minyard Acked-by: David Kershner Acked-by: Mark Brown Acked-by: Rafael J. Wysocki Acked-by: Srinivas Kandagatla Acked-by: Wolfram Sang # for the I2C parts Acked-by: Rob Herring Signed-off-by: Suzuki K Poulose Signed-off-by: Greg Kroah-Hartman

PCI: Add pci_dev_id() helper

2019-04-29T21:12:05Z

In several places in the kernel we find PCI_DEVID used like this: PCI_DEVID(dev->bus->number, dev->devfn) Add a "pci_dev_id(struct pci_dev *dev)" helper to simplify callers. Signed-off-by: Heiner Kallweit Signed-off-by: Bjorn Helgaas

PCI: Tidy comments

2018-03-19T19:20:43Z

Remove pointless comments that tell us the file name, remove blank line comments, follow multi-line comment conventions. No functional change intended. Signed-off-by: Bjorn Helgaas

PCI: Add SPDX GPL-2.0 when no license was specified

2018-01-26T17:45:16Z

b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to files with no license") added SPDX GPL-2.0 to several PCI files that previously contained no license information. Add SPDX GPL-2.0 to all other PCI files that did not contain any license information and hence were under the default GPL version 2 license of the kernel. Signed-off-by: Bjorn Helgaas Reviewed-by: Greg Kroah-Hartman

PCI: Add device flag PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT

2017-04-13T23:49:50Z

Add a new quirk flag PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT to limit the DMA alias search to go no further than the bridge where the IOMMU unit is attached. The flag will be used to indicate a bridge device which forwards the address translation requests to the IOMMU, i.e., where the interrupt and DMA requests leave the PCIe hierarchy and go into the system blocks. Usually this happens at the PCI RC, so this flag is not needed. But on systems where there are bridges that introduce aliases above the IOMMU, this flag prevents pci_for_each_dma_alias() from generating aliases that the IOMMU will never see. The function pci_for_each_dma_alias() is updated to stop when it see a bridge with this flag set. Link: https://bugzilla.kernel.org/show_bug.cgi?id=195447 Signed-off-by: Jayachandran C Signed-off-by: Bjorn Helgaas Reviewed-by: Robin Murphy Acked-by: David Daney

PCI: Add support for multiple DMA aliases

2016-04-11T19:34:32Z

Solve IOMMU support issues with PCIe non-transparent bridges that use Requester ID look-up tables (RID-LUT), e.g., the PEX8733. The NTB connects devices in two independent PCI domains. Devices separated by the NTB are not able to discover each other. A PCI packet being forwared from one domain to another has to have its RID modified so it appears on correct bus and completions are forwarded back to the original domain through the NTB. The RID is translated using a preprogrammed table (LUT) and the PCI packet propagates upstream away from the NTB. If the destination system has IOMMU enabled, the packet will be discarded because the new RID is unknown to the IOMMU. Adding a DMA alias for the new RID allows IOMMU to properly recognize the packet. Each device behind the NTB has a unique RID assigned in the RID-LUT. The current DMA alias implementation supports only a single alias, so it's not possible to support mutiple devices behind the NTB when IOMMU is enabled. Enable all possible aliases on a given bus (256) that are stored in a bitset. Alias devfn is directly translated to a bit number. The bitset is not allocated for devices that have no need for DMA aliases. More details can be found in the following article: http://www.plxtech.com/files/pdf/technical/expresslane/RTC_Enabling%20MulitHostSystemDesigns.pdf Signed-off-by: Jacek Lawrynowicz Signed-off-by: Bjorn Helgaas Reviewed-by: Alex Williamson Acked-by: David Woodhouse Acked-by: Joerg Roedel

PCI: Delete unnecessary NULL pointer checks

2014-11-11T04:02:17Z

The functions pci_dev_put(), pci_pme_wakeup_bus(), and put_device() return immediately if their argument is NULL. Thus the test before the call is not needed. Remove these unnecessary tests. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring Signed-off-by: Bjorn Helgaas

PCI: Remove unused pci_find_upstream_pcie_bridge()

2014-09-22T20:46:13Z

pci_find_upstream_pcie_bridge() is unused, so remove it. Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas